"Terrified" Michelina Lewandowska, 27, was bound by her hands and feet and left to die in a shallow grave, Leeds Crown Court was told.

In a bid to stop her getting free Marcin Kasprzak, her partner and father of their two-year-old son, had a friend help him bury her in a box less than 2ft high and then covered it in soil and leaves and then put a large branch over the top, a jury heard.

But she eventually managed to free herself and raise the alarm.

A jury was told how Kasprzak, 25, had decided that he no longer wanted to live with his partner and wanted his mother to bring up their young son.

In a bid to get her out of the way he used a 300,000 volt electric stun gun on her at their home in Waterloo, Huddersfield, West Yorks, before using parcel tape to gag her and tie her hands and feet.

Then, along with his teenage accomplice Patrick Borys, now 18, he allegedly tricked her into a 22in cardboard box, used for holding a computer, and drove her to woodland where the box was buried.

The jury at Leeds Crown Court was told that the box was placed in a natural hollow in the ground and covered over with earth and leaves before the tree branch was laid on top.

Jonathan Sharp, prosecuting, told the jury that the case was about a young man who had got bored with his partner, the mother of their child, now 3, and "decided to get rid of her".

Armed with a stun gun, he attacked her and then along with Borys, tied her up with tape, he said.

Miss Lewandowska was terrified, said Mr Sharp, and would have done anything her partner wanted.

He was not satisfied with that, the jury was told and the defendants "imprisoned" her in a cardboard box, drove her to woodland where she was unlikely to be found and buried her alive after digging a shallow grave.

After allegedly leaving his partner to die, Kasprzak and his co-accused used her bank card to get £500 from a nearby cash machine, he said.

But, against all the odds, she managed to escape and raise the alarm, Mr Sharp said, opening the case for the prosecution.

The jury was told that after having their baby son Jakub, the relationship between Kasprzak and his partner deteriorated before the attack in May.

Kasprzak told his partner that she was not as good-looking as the girls he saw at the gym and would go out with friends, sometimes staying out all night, rather than spending time with her, Mr Sharp said.

He was thinking about starting a relationship with another woman and had changed his Facebook status to single, the prosecutor added.

Eventually he came to the conclusion that the only way forward was for him and his mother to look after the baby and that "one way or another, Michelina should be got out of the way".

He allegedly persuaded Borys, to help him.

After Jakub had been taken out by his grandmother, Michelina was attacked with a stun gun but it failed to paralyse her, so they bound and gagged her with tape, the prosecutor said.

Kasprzak, then allegedly told her how much he hated her and I would be better for her to go away and leave Jakub with him and his mother and she would never see them again.

The victim was "terrified" and agreed to do whatever he wanted and agreed to leave her son with him, said Mr Sharp.

At one stage her gag and the tape on her wrists was loosened and she was given something to eat, he said. Kasprzak then allegedly told her he would take her somewhere and leave her there and asked her if she wanted to go to Oldham where she worked and where her sister lived.

But the mood changed again and after bagging up her clothes and dumping them outside, Michelina was put in a cardboard box, he said.

She was told she needed to be in the box so she could be smuggled past Kasprzak's father who was outside the house.

The box was put in the boot of her partner's Vauxhall Astra and driven to nearby Woodside Road before they went into woodland where they dug a hole in a dip in the ground.

Mr Sharp said: "They carried Michelina, sealed in the box up the hill, placed her in the hole and then piled earth both around and on top of the box. They found a large branch, weighing some 40kg and placed it across the box."

He said the victim had been "fully aware" of what was happening but was too terrified to say or do anything, meaning that as far as the defendants knew she was already unconscious.

Heaving buried her, the jury was told, they "simply left her there".

The jury was told that in burying someone alive it was well known that they would die from a lack of oxygen "in a very short time".

Mr Sharp said the defendants knew that and when they put Michelina in the shallow grave "they intended to kill her"

Eventually and "with great difficulty" she managed to get out of the box and managed to stop a passing car to raise the alarm.

When the two defendants were arrested, Kasprzak refused to answer questions and his co defendant lied, Mr Sharp told the jury.